[ now this defect seems to be fixed in VirtualBox. I let this article here just in case of a regression ]

I had no problem to install theWindows 8 Consumer Preview under VirtualBox 4.1.10 until I tried to install the Guest Additions of VirtualBox. Unfortunately I needed them to share files.The problem lies in the video adapter driver: during the installation of the Additions, and after a system reboot, a horrible black screen appears.

The solution

With this solution, the Additions work, except the video driver (we have to disable it).But you can share files, at least.

(I’ve done the procedure on a French installation, so I had to translate the texts here, they can be slightly different on an English installation)

Ensure the configuration of your virtual computer uses the 3D acceleration and uses 128 MB video RAM.I’m not sure these two settings are necessary, but the procedure works with them.

Run your virtual computer and Windows 8 in normal (not safe) mode, then open an administrator session.

Start the installation of the Guest Additions of VirtualBox.You can notice the installation of the experimental Direct3D driver cannot be unchecked.

When Windows asks you, for the first time, if you want to install an Oracle driver, tick “Alway trust the drivers from Oracle” (or something similar to that text).

The installation goes on until the screen goes black.From here, wait a few minutes (maybe two) to let the installer enough time to conclude its job, because it is not frozen, even if we cannot see it working.

Third step: disable the VirtualBox’ video driver

Now reboot the virtual computer by force.

Start Windows 8 in safe boot mode.The first time, Windows reboot one more time, it’s ok.

In safe mode, open an administrator session.

Open the hardware settings panel:Windows+R and enter the nameDEVMGMT.MSC